首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
More boys than girls arc born all over the world, but a new study has found that the closer people live to the equator, the smal
More boys than girls arc born all over the world, but a new study has found that the closer people live to the equator, the smal
admin
2016-08-02
52
问题
More boys than girls arc born all over the world, but a new study has found that the closer people live to the equator, the smaller the difference becomes. No one knows why.
The skewed sex ratio at birth has been known for more than a hundred years, and researchers have found a large variety of social, economic and biological factors that correlate with it—war, economic stress, age, diet, selective abortion or infanticide and more. Teasing out the contribution of any single cultural or political variable has proved an almost infinitely complicated exercise.
But latitude is a natural phenomenon, unaffected by cultural or economic factors. To look at its effect, Kristen J. Navara of the University of Georgia used the latitude of the capital city in 202 countries, as well as 10 years of data on sex ratio at birth and annual variations in day length and temperature.
To estimate socioeconomic status for each country, she used statistics on unemployment and gross national product. She also calculated a political instability index using an analysis of stale failure and conflict published by the Fund for Peace, a research organization that combines 12 social, economic and political indicators to estimate the relative stability of the world’s nations.
Then Dr. Navara performed a statistical analysis to figure out which variables affect sex ratio. The report appeared online April 1 in Biology Letters.
The number of boys born was not related to socioeconomic and political factors, but there was a significant correlation between sex ratios skewed in favor of boys and latitude and the climate variables that go with it. African countries produced the lowest sex ratios—50. 7 percent boys and European and Asian countries had the highest with 51. 4 percent.
The effect of latitude, Dr. Navara found, persisted across wide variations in lifestyle and socioeconomic status. There were large differences in sex ratio between tropical regions within 23 degrees of the equator and the temperate regions 23 to 50 degrees north or south, but no difference between the temperate regions and the subarctic north of 50 degrees. The population of people living south of 50 degrees was too small to be included in the analysis.
The correlation with latitude was unchanged even after excluding data from Asian and African countries that might have been skewed by abortion or the killing of baby girls. So sex selection by parents before or at birth does not explain the correlation.
The sex ratio at birth______.
选项
A、rests to some extent with the distance to equator
B、is mainly determined by abortion or infanticide
C、correlates only with cultural or economic factors
D、related to every single cultural or political variable
答案
A
解析
根据第一段中的“…a new study has found that the closer people live to the equator,thesmaller the differenee becomes”,A应为答案。
转载请注明原文地址:https://kaotiyun.com/show/72oZ777K
0
考研英语一
相关试题推荐
Bankershavebeenblamingthemselvesfortheirtroublesinpublic.Behindthescenes,theyhavebeentakingaimatsomeoneelse:
RichardRortywasoneofthemosttalked-aboutthinkersinAmerica.EveryprofessionalphilosopherintheEnglish-speakingworld
Americanschoolsaren’texactlyfrozenintime,butconsideringthepaceofchangeinotherareasoflife,ourpublicschoolste
Harvardthrilledmiddle-classparentslastweekbycappingitstuitionforfamilieswithincomesofupto$180,000at10percent
Shortlybeforehediedoflymphoma,thegreatwriterandphysicianLewisThomas,whosebooksturnedscienceintoawayofapprec
Thosedaysarelonggonewhenplacingatelephonecallmeantsimplypickingupthereceiverandaskingtheoperatortopatchyou
Thedestructionofournaturalresourcesandcontaminationofourfoodsupplycontinuetooccur,largelybecauseoftheextreme
Thetranslatormusthaveanexcellent,up-to-dateknowledgeofhissourcelanguages,full【C1】______inthehandlingofhistarget
Thetranslatormusthaveanexcellent,up-to-dateknowledgeofhissourcelanguages,full【C1】______inthehandlingofhistarget
Thetranslatormusthaveanexcellent,up-to-dateknowledgeofhissourcelanguages,full【C1】______inthehandlingofhistarget
随机试题
欲做一个容积为Vm3的无盖圆柱形储粮桶,底用铝制。侧壁用木板制,已知每平米铝价是木板价的5倍,问怎样做才能使费用最少。
男性患者,32岁,1年前诊断为右肾结核行右肾切除术,术后继续使用抗结核药物,但尿频不见好转。IVP(静脉肾盂造影)示左肾轻度积水,膀胱如乒乓球大小。治疗应考虑
防治疾病的基本原则是:
某患者,女,25岁,右乳房外上象限有一肿块,3cm×3cm,质韧、光滑、边界清楚,易推动,诊断首先考虑()
硅酮建筑密封膏的类型中,()类为镶装玻璃用密封膏,主要用于镶嵌玻璃和建筑门、窗的密封。
高级神经活动类型中“强一平衡一不灵活”型与下列哪种气质类型相对应?()
关于能力,下列说法正确的是()
Whatwillthewomanwear?
HowmanycompaniesarepresentingproductsintheConsumerElectronicsShow?
A、Americansaretooattachedtotheircars.B、Americancarsaretoofast.C、Automobilesthreatenhumanhealth.D、Automobilesare
最新回复
(
0
)